A former secret service agent has called for the re-opening of Whitney Houston's death investigation saying its the only way to solve the mystery behind her daughter Bobbi Kristina's eerily similar death From The National Enquirer John A. Carman, a former Secret Service agent, told The National Enquirer, “This smacks of a double cover-up!” Meanwhile, this publication has also learned another investigator, Isaac Weishaupt, has determined there is enough “evidence” to show the deaths could be related in both circumstance — and motive. Both deaths are linked by a combination of drugs and Bobbi Kristina’s abusive boyfriend, Nick Gordon, 25, who was either near or at both death scenes. “Whitney Houston ends up dead in a bathtub, covered with bruises, under hinky circumstances,” declared John. “Three years later, (Bobbi Kristina) dies in a bathtub, also covered with bruises, under hinky circumstances.” John, who has worked hundreds of drug cases, said to solve the ca...